1. You have an isotope with a half-life of 200 years. How much of the original material is
left after 600 years? (Answer with a fraction or percent)

What is the function of the somatic nervous system? connects the brain and the spinal cord to the rest of the body carry signals to the muscles and glands includes all nerves controlling the muscular system and external sensory receptors controls internal organs like the heart and bladder

Restless tectonic plates move (shift) between one and fifteen centimeters per year month day minute

Read each description below and determine to which stage of sleep each pertains. then click and drag each box into the appropriate category below.